Slow TM Backup?

[ISKOTB]

I run my TM every 10 days or so on a 1GB USB WD/Elements HDD. Once the backup process starts, it says it will take about 2 or less. Then it goes to this stage “SC below” and then it takes about 4 more hours to finish.
Can I do anything before the backup to speed the TM process? Never seen this on Mojave

Thank You!

 

[chrfr]

I run my TM every 10 days or so on a 1GB USB WD/Elements HDD. Once the backup process starts, it says it will take about 2 or less. Then it goes to this stage “SC below” and then it takes about 4 more hours to finish.
Can I do anything before the backup to speed the TM process? Never seen this on Mojave

Thank You!

Time Machine is having to clear space on your disk because the backup disk is too full to fit your backup. That's what the "Freeing space" step is, and it takes a long time on any version of macOS. If you manually delete some backups and free up a bunch of space before your backup begins, it'll go much faster.

 

[IowaLynn]

Old rule of thumb: TM drive should be 3.5x capacity of source drive(s)

Good idea to start fresh with Catalina.

Also, a separate clone backup drive. CCC can do a lot to help insure bootable backup and file version.

Writing 100GB you should have more like 200-300GB free.